package com.hqyj.javaSpringBoot.interceptor;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import org.springframework.ui.ModelMap;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * @Description：ViewMappingInterceptor
 * 自动封装 template 路径
 * 约定：目标页面的相对路径地址与 path 路径保持一致
 * @Author ：Cwd
 * @Date ：2021/8/23 13:26
 */
@Component
public class ViewMappingInterceptor implements HandlerInterceptor {

    private final static Logger LOGGER = LoggerFactory
            .getLogger(ViewMappingInterceptor.class);

    @Override
    public boolean preHandle(HttpServletRequest request,
                             HttpServletResponse response,
                             Object handler) throws Exception {
        LOGGER.debug("==== ViewMappingInterceptor Pre Handle ====");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request,
                           HttpServletResponse response,
                           Object handler, ModelAndView modelAndView) throws Exception {
        LOGGER.debug("==== ViewMappingInterceptor Post Handle ====");

        //判断请求是否返回 view ，如果是 rest 接口 || redirect || forward，则不作处理
        if (modelAndView == null ||
                modelAndView.getViewName().startsWith("redirect") ||
                modelAndView.getViewName().startsWith("forward")){
            return;
        }
        //从请求中得到 path
        String path = request.getServletPath();
        //判断 modelMap 中是否有设置 template，如果已有，则无需设置
        ModelMap modelMap = modelAndView.getModelMap();
        String template = (String)modelMap.get("template");
        if (StringUtils.isBlank(template)){
            path = path.startsWith("/") ? path.substring(1) : path;
            //在modelMap 中设置 template，值为 path
            modelAndView.getModelMap().addAttribute("template",path);
        }
    }

    @Override
    public void afterCompletion(HttpServletRequest request,
                                HttpServletResponse response,
                                Object handler, Exception ex) throws Exception {
        LOGGER.debug("==== ViewMappingInterceptor After Handle ====");
    }
}
